This invention relates to a disk guide for a system for handling disks such as semiconductor wafers and more particularly to a disk guide for slidingly lifting such a disk supported from both sides by a pair of grooves. Semiconductor wafers are fragile or otherwise easy to be rendered useless by contamination or abrasion. Thus, automatic disk handling systems are commonly used to move such disks one at a time from one work station to another and from one processing position to another. For this reason, it is extremely important that each disk be brought accurately to a predetermined position such that an automated disk handling system can grasp it for moving it to a next position. As a part of such a disk handling system, it is common to provide a pair of vertically oriented grooves on mutually parallel vertical sidewalls which are opposite to each other and facing each other such that a disk can not only be vertically supported in these grooves by its peripheries but also slidably move vertically along these grooves. For such a purpose, a vertically mobile disk holder is usually provided not only to support the disk between these grooves from both sides but also to lift the disk upward to a predetermined height, and the separation between the grooves is made sufficiently larger than the diameter of the disk such that the disk can smoothly slide upward inside and along the grooves, but this has the undesirable consequence that the disk cannot be accurately positioned with respect to the grooves because the disk has the freedom of moving towards and leaning against either of the two grooves.